//
//  QCCycleImages.m
//  06-CycleImages
//
//  Created by QC.L on 16/7/21.
//  Copyright © 2016年 QC.L. All rights reserved.
//

#import "QCCycleImages.h"

@interface QCCycleImages () <UIScrollViewDelegate>
@property (nonatomic, strong) UIScrollView *cycleScrollView;
@property (nonatomic, strong) UIPageControl *imagesPage;
@end

@implementation QCCycleImages

#pragma mark - scrollView Delegate
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
    // 改变pageControl的对应下标
    NSInteger page = scrollView.contentOffset.x / self.bounds.size.width;
    _imagesPage.currentPage = page - 1;
    if (page == 0) {
        // 改变滚动视图的偏移量
        _cycleScrollView.contentOffset = CGPointMake(self.bounds.size.width * (_imagesArray.count - 2), 0);
        _imagesPage.currentPage = _imagesArray.count - 1 - 2;
    } else if (page == _imagesArray.count - 1) {
        _cycleScrollView.contentOffset = CGPointMake(self.bounds.size.width, 0);
        _imagesPage.currentPage = 0;
    }
    
}
#pragma mark - init
- (instancetype)initWithFrame:(CGRect)frame {
    self = [super initWithFrame:frame];
    if (self) {
        // 子控件初始化时, frame不要与初始化方法的frame一样
        // 推荐使用 self.bounds / CGRectMake(0, 0, frame.size.width, frame.size.height)
        [self initCycleScrollView];
        [self initImagePage:frame];
    }
    return self;
}

- (void)initCycleScrollView {
    _cycleScrollView = [[UIScrollView alloc] initWithFrame:self.bounds];
    _cycleScrollView.pagingEnabled = YES;
    _cycleScrollView.bounces = NO;
    _cycleScrollView.delegate = self;
    _cycleScrollView.showsHorizontalScrollIndicator = NO;
    [self addSubview:_cycleScrollView];
}
#warning 后期需要添加page的位置改变, 这里默认位置
- (void)initImagePage:(CGRect)frame {
    _imagesPage = [[UIPageControl alloc] initWithFrame:CGRectMake(0, 0, frame.size.width / 3, 30)];
    _imagesPage.numberOfPages = 5;
    _imagesPage.center = CGPointMake(frame.size.width / 2, frame.size.height - 30 / 2);
    [self addSubview:_imagesPage];
    [_imagesPage addTarget:self action:@selector(imagePageChange:) forControlEvents:UIControlEventValueChanged];
}
// 问题: 如何通过pageControl进行轮播
- (void)imagePageChange:(UIPageControl *)pageControl {
    [_cycleScrollView setContentOffset:CGPointMake((pageControl.currentPage + 1) * self.bounds.size.width, 0) animated:YES];
}
#pragma mark - ImagesArray
- (void)setImagesWithArray:(NSArray *)array {
    // 1.根据传过来的数组, 进行处理, 生成图片数组
    NSArray *imagesArray = [self handleArray:array];
    // 2.逻辑判断时, 需要用到数组内容
    self.imagesArray = imagesArray;
    // 3.根据数组生成对应的ImageView
    [self createAllImageViewsWithImagesArray:imagesArray];
    // 根据图片数组, 设置对应的视图
    _imagesPage.numberOfPages = array.count;
    _cycleScrollView.contentSize = CGSizeMake(imagesArray.count * self.bounds.size.width, 0);
    // 因为添加了最后一张图, 要让轮播图看起来在第一张
    _cycleScrollView.contentOffset = CGPointMake(self.bounds.size.width, 0);
}

- (NSArray *)handleArray:(NSArray *)array {
    // 判断类型(不知道别人使用你的类的时候传进来的类型是什么)
    id firstObject = [array firstObject];
    // 最终的图片数组
    NSMutableArray *imagesArray = [NSMutableArray array];
    // 判断对象是不是某种类型 isKindOfClass
    if ([firstObject isKindOfClass:[NSString class]]) {
        // 把 字符串 数组 转成 UIImage 数组
        for (NSString *imageName in array) {
            UIImage *image = [UIImage imageNamed:imageName];
            [imagesArray addObject:image];
        }
    } else if ([firstObject isKindOfClass:[UIImage class]]) {
        [imagesArray setArray:array];
    }
    // 获取到第一张图
    UIImage *firstImage = [imagesArray firstObject];
    // 获取到最后一张图
    UIImage *lastImage = [imagesArray lastObject];
    // 下标为0的位置放最后一张图
    [imagesArray insertObject:lastImage atIndex:0];
    // 在最后添加第一张图
    [imagesArray addObject:firstImage];
    
    return [imagesArray copy];
}

- (void)createAllImageViewsWithImagesArray:(NSArray *)imagesArray {
    for (int i = 0; i < imagesArray.count; i++) {
        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(i * self.bounds.size.width, 0, self.bounds.size.width, self.bounds.size.height)];
        imageView.image = imagesArray[i];
        [_cycleScrollView addSubview:imageView];
    }
}



/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code
}
*/

@end
